Sitting itself may not be the problem; it may be a marker for other risk factors that would be associated with higher mortality.
But emotional stress may be a marker for other risk factors and not necessarily a risk in itself, Dr. Goldberg added.
In other words, walking speed seemed to be independently associated with life expectancy, not just a marker for other conditions that would affect it.
"Thus, a low vitamin D level may be a marker for other conditions, but not necessarily a direct cause of disease," says Dr. Manson.
Excessive drinking is a problematic behaviour in its own right but it is also a marker for other problem behaviours, including illicit drug misuse and delinquency.
Although sodium is believed to be just a trace in the Moon's atmosphere, it is studied because it is relatively easy to detect and is used as a marker for other components, like potassium, neon, argon and helium.
They added that the studies leave open the possibility that sunburn "is merely a marker for other, unremembered exposures to sunlight," meaning that it may not be the sunburns themselves but rather sun exposure in general that increases melanoma risk.
Extant research affirms that angel investors seek passionate entrepreneurs but questions surround whether there is value in passion itself, or if it is instead used as a marker for other important characteristics like tenacity and inspirational leadership.
There is a feedback loop between biology and the social environment that gives to those who have, and takes from those who have not.That happens because beauty is a real marker for other, underlying characteristics such as health, good genes and intelligence.
Race may also be a marker for other demographic or behavioral risk factors.
It could be that spicy food is just a marker for other lifestyle choices that lead to good health.
